qcow2: Leave s unchanged on qcow2_update_options() failure

On return, either all new options should be applied to BDRVQcowState (on
success), or all of the old settings should be preserved (on failure).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2015-04-16 13:11:39 +02:00
parent 94edf3fbe8
commit 007dbc396c
1 changed files with 35 additions and 22 deletions

View File

@ -597,7 +597,10 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options,
const char *opt_overlap_check, *opt_overlap_check_template;
int overlap_check_template = 0;
uint64_t l2_cache_size, refcount_cache_size;
Qcow2Cache *l2_table_cache;
Qcow2Cache *refcount_block_cache;
uint64_t cache_clean_interval;
bool use_lazy_refcounts;
int i;
Error *local_err = NULL;
int ret;
@ -640,9 +643,9 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options,
}
/* alloc L2 table/refcount block cache */
s->l2_table_cache = qcow2_cache_create(bs, l2_cache_size);
s->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size);
if (s->l2_table_cache == NULL || s->refcount_block_cache == NULL) {
l2_table_cache = qcow2_cache_create(bs, l2_cache_size);
refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size);
if (l2_table_cache == NULL || refcount_block_cache == NULL) {
error_setg(errp, "Could not allocate metadata caches");
ret = -ENOMEM;
goto fail;
@ -656,23 +659,18 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options,
ret = -EINVAL;
goto fail;
}
s->cache_clean_interval = cache_clean_interval;
cache_clean_timer_init(bs, bdrv_get_aio_context(bs));
/* Enable lazy_refcounts according to image and command line options */
s->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS,
use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS,
(s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS));
if (use_lazy_refcounts && s->qcow_version < 3) {
error_setg(errp, "Lazy refcounts require a qcow2 image with at least "
"qemu 1.1 compatibility level");
ret = -EINVAL;
goto fail;
}
s->discard_passthrough[QCOW2_DISCARD_NEVER] = false;
s->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true;
s->discard_passthrough[QCOW2_DISCARD_REQUEST] =
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST,
flags & BDRV_O_UNMAP);
s->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] =
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true);
s->discard_passthrough[QCOW2_DISCARD_OTHER] =
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false);
/* Overlap check options */
opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP);
opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE);
if (opt_overlap_check_template && opt_overlap_check &&
@ -704,6 +702,10 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options,
goto fail;
}
/*
* Start updating fields in BDRVQcow2State.
* After this point no failure is allowed any more.
*/
s->overlap_check = 0;
for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) {
/* overlap-check defines a template bitmask, but every flag may be
@ -713,12 +715,23 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options,
overlap_check_template & (1 << i)) << i;
}
if (s->use_lazy_refcounts && s->qcow_version < 3) {
error_setg(errp, "Lazy refcounts require a qcow2 image with at least "
"qemu 1.1 compatibility level");
ret = -EINVAL;
goto fail;
}
s->l2_table_cache = l2_table_cache;
s->refcount_block_cache = refcount_block_cache;
s->use_lazy_refcounts = use_lazy_refcounts;
s->discard_passthrough[QCOW2_DISCARD_NEVER] = false;
s->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true;
s->discard_passthrough[QCOW2_DISCARD_REQUEST] =
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST,
flags & BDRV_O_UNMAP);
s->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] =
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true);
s->discard_passthrough[QCOW2_DISCARD_OTHER] =
qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false);
s->cache_clean_interval = cache_clean_interval;
cache_clean_timer_init(bs, bdrv_get_aio_context(bs));
ret = 0;
fail: